2 hours ago, cgsheen1 said:

warm to cold...

1 hour ago, chaseincats said:

I 100% agree but in this case its been 6 full years without leaking

Sounds like you don't agree 100%.

We're just offering possibilities. It's actually more interesting to some of us that the fitting was 3/4 turn loose and did not leak sooner.

If it was mine I'd pull that line and make sure I didn't need more parts before starting the MC replacement. Might find out that you don't need a new MC, you actually need a new hard line.

Or a new flare on that tube and maybe a new flare nut. I'd venture a guess that it didn't go 6 years without any leak at all - probably just one that was slight and unnoticed... (just like many plumbing leaks)

4 hours ago, Zed Head said:

Sounds like you don't agree 100%.

We're just offering possibilities. It's actually more interesting to some of us that the fitting was 3/4 turn loose and did not leak sooner.

If it was mine I'd pull that line and make sure I didn't need more parts before starting the MC replacement. Might find out that you don't need a new MC, you actually need a new hard line.

3 minutes ago, cgsheen1 said:

Or a new flare on that tube and maybe a new flare nut. I'd venture a guess that it didn't go 6 years without any leak at all - probably just one that was slight and unnoticed... (just like many plumbing leaks)

that makes sense

Update for all of you. We very may be in business here and you were all right - the hydraulic line was crooked/not fully seated and once I took it out and reseated it, the leak was gone. Again, I still don't understand how it didn't leak over the course of 6 years and thousands of miles, but I guess that was a good thing. I am going to bleed the brakes tomorrow just to be safe but I did bleed the master after all of this and the pedal feels good.

Here are pictures of the line screwed in before, the flange/nut's condition when I took it out this evening, and how the cylinder looks now with the line in straight.

Awesome.

MAN remember the heady days of me celebrating that it was just a matter of screwing something in? Man those were the days.

I took it out tonight and within about a minute or so of using the brake pedal it went pretty much straight to the floor now that it was stopping mass I guess. I headed back home and now there is fluid leaking out of the bottom of both where the front and rear brake lines screw in.

Time to trash this master, right?

Probably need to put some thought into replacing the short lines. You need to do an evaluation of what condition of the parts you’re working with.

On 12/9/2025 at 10:15 PM, Yarb said:

Probably need to put some thought into replacing the short lines. You need to do an evaluation of what condition of the parts you’re working with.

so I swapped out the master last night and it’s unfortunately still leaking in the same spot so it has to be the line at this point like you were saying?

Edited yesterday at 02:40 AM1 day by chaseincats

On 12/4/2025 at 12:48 PM, Zed Head said:

It's also possible that the metal to metal seal of the brake line was damaged when you changed the MC the first time. Pretty common for the tube to twist with the fitting when the fitting is loosened.

The only way to be sure is to examine the parts. A magnifying glass and bright lights help. Take a close look and you'll see where the actual sealing surface is. A spec of foreign matter can screw things up. Something to be aware of if you do change the MC. The threads don't do the sealing, they just do the clamping.

You can see the cone that fits inside the end of the tube in this image from Rockauto. That's the sealing surface.

Bright light and a magnifying glass will tell you a lot. Inside of the cone at the end of the metal line and outside of the cone down the hole. You might see a crack or deformation. You could even polish the surfaces if they look rough. Also polish the surface that the fitting rides on. It needs to be smooth so that the fitting can apply even pressure across the bell shape at the end of the metal tube. Focus on the surfaces that make contact. The threads are only there to apply the force.